Valve-operating gear for engines.



Patented Bot. 22, |90|. 8. Z. DE FERRANTI. VALVE OPERATING GEAR FOBENGINES.

(Application filed July 81, 1900.)

9 Sheets-Sheet I.

(No Model.)

IN VENTOH" WITNESSES ATTORNEYS m: "cams PETERS co. PHQTO-LITHOY.WASHINGTOL n. c

No. 684,926. Patented Oct. 22, I90I. 3. Z. DE FERRANTI.

VALVE OPERATING GEAR FOR ENGINES.

(Application filed July 31, 1900.)

9 Sheets Sheet '2.

AfTORNEYS (No Model.)

s. 2. ma FERBANTI. VALVE OPERATING GEAR FOR ENGINES.

( Application filed July 31, 1900.)

WITNESSES:

Patented Oct. 22, I90l- 9 Shets-Shaet 3.

A g T Q) r i g I a IN VEN TOR A TTOHNE YS Patented Oct. 22, l90l. 8. 2.DE FEHRANTI. VALVE OPERATING GEAR FOR ENGINES.

(Application filed July 31, 1900.)

9 Sheets-Sheet 4.

(No Model.)

Fig.2

.l/V VENTOR WITNESSES AITORNE N THE NORRIS PETERS cw. PHOY umo musumowuu c N0. 684,926. Patented Oct. 22, 1901. 8. Z. DE FERRANTI.

VALVE OPERATING GEAR FOR ENGINES.

(Application filed m 31, 1900.

9 Sheets-Sheet 6.

(No Model.)

WITNESSES."

AfTDR/VEYS No. 684,926. Patented Oct. 22, [90L 8. Z. DE FEBBANTI.

VALVE OPERATING GEAR FOR ENGINES.

(Applies-titan filed July 31, 1900.)

9 Sheets-Sheet 7.

(No Model.)

INVENTOR ATTUfi/Vf XS wi g; a; M

W/TNESSES: 51A

@ZZZM No. 684,926. Patented Oct. 22, I901.- s. 2. DE FERRANTI.

VALVE OPERATING GEAR FOR ENGINES.

(Application filed July 31, 1900.) (No Model.) 9 Sheets-Sheet 8.

FIG. 14.

IN G V INVENTOH WITNESSES. aflmw W W A [TOHNE rs Patented out. 22, 1901.s. 2; ma FERRANTI. VALVE OPERATING GEARv FOR ENGINES.

(Application filed. July 31, 1900.)

9 Sheet-$haat 9., 7

(No Model.)

Arron/v6 rs THE Numus vzrcns ca. Putnam-Nu. WASHINGTON. u. c.

NITED STATES PATENT OFFICE.

SEBASTIAN ZIANI DE FERRANTI, OF HOLLINGWOOD, ENGLAND.

VALVE-OPERATING GEAR FOR ENGINES.

SPECIFICATION forming part of Letters Patent No. 684,926, dated October22, 1901. Application filed July 31, 1900. Serial No. 25.428. (Nomodel.)

To all whom it may concern.-

Be it known thatLSEBASTIAN ZIANI DE FER- RANTI, engineer, a subject ofthe Queen of Great Britain and Ireland, and a resident of Hollingwood,in the county of Lancaster, Eng- 1and, have invented certain new anduseful Improvements in Valve Operating and Governing Gear forSteam-Engines, (for which I have made application for Letters Patent inGreat Britain, No. 3,536,'dated February 22, 1900,) of which thefollowing isaspecification.

My invention relates principally to highspeed steam-engines; and myobject is to produce a high-speed engine having a very eifectiveautomatic cut-off valve and governlug-gear.

In high-speed engines as hitherto. constructed it has been foundimpossible to govern eifectively by automatic cut-off, as the onlyeffective automatic cut-off devices in use are those which depend upontrip-gear, and as an effective trip-gear requires sharplydefined edgesin contact, trip-gear engines, such as the Well-known Corliss-typeengine, have not been run at high speeds. Accordingly, existingreciprocating high-speed engines are governed mainly by throttling thesteam-supply.

My invention consists in certain novel devices and combinations, as willbe hereinafter fully described and pointed out in the claims.

Referring now to the accompanying drawings, which illustrate one form ofmy invention as applied to a compound vertical steamengine, Figure 1 isa plan of the engine with the crank-shaft and other lower parts removed.Fig. 2 is a sectional elevation of the same, the section being taken onthe line E E of Fig. 1. Fig. 3 is a sectional elevation through thevalve-casing a. Fig. 4. is a section of the valve-casing a, the sectionbeing taken on the lines A A of Figs. 3, 5, 6, and 7. Fig. 5 is a planof the valve-casing. Fig. 6 is a'sectional plan of the same, the sectionbeing taken on the line B B B B of Fig. 3. Fig. 7 is another sectionalplan of the same, the section being taken on the line C O of Fig. 3.Fig. Sshows one of the cam-shafts with the cams, screwed sleeves,sliding nut, cross-piece, and skew-wheel in section. Fig. 9 showsthescrewed sleeves for actuating the valve closing cams. Fig. 10 is asection taken on the line D D of Fig. 8 and illustrates the method ofrotating the valve-clos ing cams on the cam-shaft. Fig. 11 is a diagrammatic View illustrating the opening and closing of the steam-valves.Fig. 12 similarly illustrates the opening and closing of theexhaust-valves. Fig. 13 is abridle or slide, by means of which thesteam-cams actuate the valves. Fig. 14 is a bridle or slide, by means ofwhich the exhaust-cams actuate the valves. Fig. 15 is a section throughthe oil-relay cylinder, showing its connection with the gov A is thelow-pressure, and B the high-pressure, cylinder. Each cylinder has asteamvalve and an exhaust-valve at the top and a steam and an exhaustvalve at the bottom. These valves are preferably grid-valves and covernearly the whole of the top and bottom of the cylinders.

G O are the steam-valves, and D D the exhaust-valves.

EE are the pistons, and F F the pistonrods.

G is a vertical shaft driven by gearing from the crank-shaft anddriving, by means of the bevel-wheels H and K, the horizontal shaft L.This shaft L carries a skew-wheel M, which .drives the cam-shafts, aswill be described hereinafter. The shaft L also drives the governor N bymeans of the bevel-wheels O and P.

The valve-casing a is situated between the high-pressure and thelow-pressure cylinders and is full of oil, which is supplied from thereservoir T. Inside the casing a are two cam-shafts b and c, which arerotated by the horizontal shaft L by means of the skewwheels M, Q, and R(see Fig. 3) at half the speed of the engine crank-shaft. The camshaft bcarries at its upper part the fixed cams h and Z and the moving cam isand at its lower part the moving cam m and the fixed cams n and 0. Thecams h and k are for operating the steam-valve at the upper end of thelow-pressure cylinder, and the cam 'l is for operating the exhaust-valveat the top of the high-pressure cylinder. The cams m and n are foroperating the steam-Valves at the lower end of the low-pressurecylinder, and the cam. o operates the lower exhaust-valve of thehigh-pressure cylinder.

Each of these cams is of constant diameter-- that is, any depression onthe one side is counterbalanced by a corresponding projection on theother side. The steam-cams actuate the valves through the agency ofslides or bridles p, q, r, and 3, one of which is shown in plan in Fig.13. Each of these bridles carries two buffer-levers u a, each pivoted tothe bridle at one end '0 and having at its other end a small cylinder orcasing w, provided with a number of disks or plates as, which arepreferably slightly bent to give them some elasticity. Each levercarries a roller .2, which bears against one or other side of the cam,as shown in Fig. 13. An adjusting-screw y presses against the disks aswith any desired pressure, so as to press them into the cylinder w. Thepressure which the rollers z z exert on the cam is thus controlled. Asthe valvegear is intended to be immersed in oil, the disks act toproduce oil cushioning by interposing resistance to the escape of theoil film between them. A slight elasticity is thus given to the rollersand small variations from constant diameter in the cam compensated for.By this means, although the rollers z z are very firmly secured withineach bridle, a slight cushioning effect is produced which permits thecam to operate with great smoothness, notwithstanding a comparativelyrapid reciprocating movement of the bridle. It should be noted that thecy inder or casing 10 is intended merely to contain the disks and not toact as a dash-pot. Each of these bridles for actuating the steamvalvesis provided at one end with a slot 14, (see Fig. 4,) in which worksvertically a suitable block 15, pivoted to the end of the verticallevers 2 and 3. The fixed cam his thus connected by its bridle with thetop end of the lever 2 and the moving cam with the bottom end of thesame lever. Similarly the moving cam m and the fixed cam 07. areconnected to the top and bottom ends, respectively, of the lever 3.Valve-spindles at and 5 are respectively pivoted at 16 and 17 to thelevers 2 and 3 at points intermediate between theends ofthese levers.These valve-spindles by their reciprocating movement open and close thesteam-valves of the lowpress ure cylinder in a manner which can be bestunderstood by referring to Fig. 11, which illustrates the operationdiagrammatically with reference to the valve-spindle 2, which operatesthe upper steam-valve of-the low-pressure cylinder.

Let 11 be the initial position of the valve1nechanism,thevalvebeingclosed. The fixed cam-bridle (which acts on thetop of the lever) is here full in and the moving cam-bridle full out.The fixed cam-bridle now moves out, the lever turns about its lower endas a fulcrum, and the valve-spindle is moved longitudinally, opening thevalve,-as shown at 11". The moving ca1n-bridle now moves in,

the lever turns about its upper end as a fulcrum, and the valve isclosed again, as shown at 11. The fixed cam bridle now moves in, and thelever turning about its lower end again opens the valve, as shown at 11.Lastly, the outward movement of the moving cam-bridle returns the valveand mechanism to their original positions at 11. The lower steam-valveof the low-pressure cylinder is actuated by the lever 3 andvalve-spindle 5 in a similar manner. It will thus be seen that the fixedcams open the steamvalves and the moving cams close them. By alteringthe angular position of the moving cams on their shaft I can cut offsteam at any point of the stroke 1 please, while the point of steamadmission or the lead is unaltered. It will be seen that when theopening and closing cams are in opposition no steam will be admitted.

The shaft 0 is provided with cams and other valve-gear of a natureprecisely similar to that on the shaft b and is used for controlling thesteam-supply to the high-pressure cylinder of the engine.

I shall now describe how the angular position of the moving cams on thecam-shafts is controlled. I provide a cross-piece 6, which is adapted tobe moved up and down by a governor or combination of governors or by arelay controlled by a governor. This crosspiece carries a nut 7 at eachend, the nuts inclosing the cam-shafts b and 0. Each nut is able torotate in the end of the cross-piece and is screwed internally with twovery quick threads, one right hand and the other left hand, whichengage, respectively, with two similar threads cut on the outside of twosleeves 8 and 9, Figs. 8, 4, 7, 8, and 9. The sleeve 8 is rigidlyattached to the cam-shaft, and therefore revolves with it. The othersleeve 9 is formed in one piece with the moving cam it. Therefore if thenut 7 be moved parallel to the axis of the shaft it will rotate acertain amount relatively to the shaft in one direction and a certainamount relatively to the moving cam 7. in the other direction. Theangular displacement of the cam 7c relatively to the shaft willtherefore equal the sum of these amounts. The shaft 7) is made hollowand incloses an inner shaft 11, Figs. 8 and 10, which is keyed to themoving cams 7c and.

m by the keys 12, so that the two moving.

cams and the inner shaft rotate together. The keys 12 work in holes 13in the shaft I), which allow theinner shaft to rotate through a certainangle relatively to the cam-shaft b. Thus any movement of thecross-piece 6, parallel to the axes of the shafts, causes the movingcams 7c and m to rotate relatively to the cam-shaft, and this willhappen whether the cam-shaft be at rest or in motion. The shaft 0,carrying the cams for controlling the steam-supply to the high-pressurecylinder, is provided with similar mechanism which acts in a similarmanner.

The exhaust-camsl and 0 on the shaft 1) are inclosed by the bridles orslides 18 and 19, one of which is shown in plan in Fig. 14

drawn to a large scale. These bridles are very similar to the bridles ofthe steam-cams hereinbefore described, except that the end of each isnot adapted to receive a sliding block, but is fitted to hold the end ofone of the exhaust-valve rods 21 between two flanges 22 and 23. Thesevalve-rods are so connected to the upper and lower exhaust-valves, re-

, spectively, of the high-pressure cylinder and open and close thevalves in the following manner, which I shall describe with reference toFig. 12: When the cam-bridle is full in, the valve-rod and valve are inthe positions shown at 12*, the valve being closed. The bridle now moveshalf-way out and the valve is opened, as shown at 12 The bridlecontinues its outward motion, and when it is full out the valve is againclosed, as shown at 12. The bridle now moves inward halfway and thevalve is. opened again, as can be seen at 12. Lastly, the bridle movesfull in and the valve returns to its position shown at 12.

It will be seen that both the steam-valves and the exhaust-valves opentwice and close twice for each cycle of movement. This allows of therotation of the cam-shaft being only half that of the crank-shaft of theengine, thereby facilitating smooth Working of the cams.

The cross-piece 6, before referred to, may advantageously be operated bymeans of a piston 24, Figs. 2 and 15, working in an oil relay-cylinder25 and connected to the crosspiece by the piston-rod 26. Theoil-cylinder receives oil through two pipes 27 and 28, having ports 31and 32 in the oil valve-cylinder 29. The ports 31 and 32 can be placedeither in communication with the ends of this valve cylinder or with thespring-controlled exhaust-valve 33 by means of a piston-valve 30. Thetop end of the cylinder communicates with the oil pressure-reservoir 34by means of the tube 35, which enters the valve-cylinder at 36, Figs. 5and 15. The lowerend of the oil valve-cylinder communicates similarlywith the oil pressure-reservoir 37 by means of the tube 38, which cannotbe seen in Fig. 15, but is seen in Figs. 1 and 5. The pistonvalve 30 iscontrolled by the governor N by means of the lever 41, pivoted at 42.This lever has at one end pins 43, which work between collars 44 on thepiston-valve spindle 45, which passes through a stuffing-box 46 at thebottom of the valve-cylinder. The other end of the lever 41 is providedwith pins 47, which work between collars 48 on the governor-spindle 49.The governor-spindle carries a dash-pot 51, containing a fixed piston52. The portion of the dash-pot below the piston contains a spring 53,and this portion is joined to the part above the piston by the passage54, which can be more or less closed by the regulating-screw 55. Thespring 53 may be dispensed with and a spring 56 ap plied to the governorinstead, or both springs may be used. The dash-pot is preferablyinclosed in a casing 57. I

An increase or decrease in the speed of the engine causes a rise orfall, respectively, in the governor-spindle 49, owing to the action ofthe governor. This causes a fall or rise in the piston-valve spindle 45and admits oil to one or other of the ports 31 or 32, while the otherport is put in communication with the exhaust-valve 33 in a manner thatis well understood. The oil-piston 24, having unequal pressures on topand bottom, therefore moves down or up and actuates the crosspiece 6,which alters the angular position of the steam-closing cams on thecam-shafts, as hereinbefore described. I connect the piston rod 26 witha pivoted lever 62, carrying a pointer 63, which traverses a scale 64.This pointer indicates on the scale the exact cut off at which thevalves are operating.

The oil pressure-reservoirs receive oil under a constant pressure frompumps 58 and 59, actuated by eccentric pins 61, on the end of thecam-shafts b and c. The spring in the discharge-valve 33 limits the rateof motion of the oil-piston 24 when very great variations in the load onthe engine suddenly occur. I By myinvention, as hereinbefore described,I perform all the steam-exhaust and governing actions by means of cams,levers, screws, and skew gear, together with hydraulic relay, allinclosed within one casing and all the cams and moving parts continuallyimmersed in oil. By this arrangement I produce a very sensitivevalve-gear which accurately determines the steam admission, steamcut-off, and the variation of steam cut-off in a smooth workingapparatus.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In valve operating and governing gear, in combination a cam-shaft,fixed and moving steam-cams carried by said shaft, means for rotatingthe moving cams relatively to the shaft, bridles reciprocated by thesaid steamcams, slots inthe ends of the bridles, blocks sliding in thesaid slots, levers pivoted to the blocks and oscillated by the bridles,valve spindles reciprocated by the levers and grid=.

valves, actuated by the valve-spindles, sub stantially as and for thepurpose described.

2. In valve operating and governing gear for steam-engines, incombination, a valvecasing, a cam-shaft adapted to rotate in oil in saidcasing, fixed and moving steam-cams of constant diameter measuredthrough the axis of rotation carried by the said shaft, a governor,means forrotating the moving cams relatively to the shaft by means ofthe governor,brid1es reciprocated by the said steamcams, slots in theend of the bridles, blocks sliding in the said slots levers pivoted tothe blocks and oscillated by the bridles, valvespindles pivoted to andreciprocated by the levers, and grid-valves actuated by the valve*spindles and adapted to be opened by the fixed cams and closed by themoving cams, substantially as and forthe purpose described.

3. In valve operating and governing gear for-steam-engines incombination, cam-shafts b and c, inner shafts 11 contained by thecamshafts, cams k and m keyed to the said inner shafts, a cross-piecesuch as 6, a nut rotatably supported at each end of the cross-piece,quick right and left hand threads in the nuts, two sleeves with rightand left hand external threads respectively adapted to engage with eachnut, one sleeve being fixed on each of the aforesaid cam-shafts and theother being rigid with one of the aforesaid cams 7a or m, substantiallyas and for the purpose described.

4. In valve operating and governing gear forsteam-engines incombination, cam-shafts such as b and a two cams h and n fixed to eachshaft, an inner shaft such as 11 inclosed in each cam-shaft, two camssuch as 70 and on keyed to each inner shaft, a governor, a crosspiecesuch as 6 controlled by the governor, a nut supported but free to rotateat each end of the cross-piece, quick right and left hand threads ineach nut, two sleeves with right and left hand external threadsrespectively adapted to engage with each nut, one sleeve being fixed onone of the said cam-shafts and the other being made in one piece withone of the said cams or at substantially as and for the purposedescribed.

5. In valve-operating gear for steam-engines, in combination a cam-shaftadapted to rotate at half the speed of the engine crankshaft,steam-opening, steam-closing'and exhaust cams carried by said cam-shaft,and steam and exhaust valves operated by said cams and adapted to openand close twice in a single cycle of their movements, snbstantially asand for the purpose described.

6. In valve operating and governing gears for steam-engines, incombination, steamvalves at both ends of the cylinder, exhaustvalves atboth ends of the cylinder, a camshaft, two steam-opening cams fixed onthe said shaft and means whereby these cams open the steam-valves, agovernor, two steamclosing cams rotatably carried by the aforesaid shaftand means whereby these cams close the steam-valves under the control ofthe governor, exhaust-cams fixed on the aforesaid shafts and meanswhereby these exhaustcams open and close the exhaust-valve,substantially as described.

7. In valve operating and governing gear forsteam-engines, incombination,steam gridvalvcs such as O at both ends of the cylinder,

seat-92c exhaust grid-valves such as D at both ends of the cylinder andalongside of the said steam-valves, a cam-shaft b, means to rotate thesaid cam-shaft at halfthe speed of the engine crank-shaft, twosteam-opening cams h and n fixed on the said cam-shaft and means wherebythese cams open the steam-valves, two steam-closing cams 7c and mrotatably carried by the aforesaid cam-sh aft and means whereby thesecams close the steamvalves, two exhaustcams Z and 0 each fixed on theaforesaid cam-shaft between a steam-opening and a steamclosing cam andmeans whereby these exhaust-cams open and close the exhaust-valves,substantially as described.

8. In valve-operating gear, the combination, with reciprocating meansfor operating the valves, of an oil-cushioning device comprising anumber of plates with oil films between them for the purpose of takingup the blows due to the inertia of the reciprocating parts,substantially as described.

9. In valve-operating gear, in combination,

a cam of constant diameter, a bridle such as p, buffer-levers pivoted tothe bridle, rollers carried one by each of said levers and adapted topress on opposite sides of the cam, a casing carried by each lever,disks, such as w retained by said casings and immersed in oil, andscrews for regulating the pressure on the disks, substantially as andfor' the purpose described. 10. In combination, two steam-cylinders, avalve-gear casing situated between said cylders and adapted to containoil, two camshafts contained in said valve-casing, two sets of cams oneach cam-shaft, each set comprising a, steam-opening and a steam-closingcam for one cylinder and an exhaust-cam for the other cylinder, thesteam-closing cams be ing adapted to be rotated relatively to thecamshafts, substantially as and for the purpose described.

11. In combination, two steam-cylinders, a valve-gear casing situatedbetween said cylinders and adapted to contain oil, two camshaftscontained in said casing, two sets of cams on each cam-shaft, each setcomprising a steam-opening and a steam-closing cam for one cylinder andan exhaust-cam for the other cylinder, the operation of both sets ofvalves being effected by the cams giving a direct push and pull betweenthe cylinders, substantially as described.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

' SEBASTIAN ZIANI DE FERRAN'JI.

Witnesses:

ALBERT G. PARKER, F. J. BIGNELL.

